Swivel and feed connection for a core drill



Sept. 7, 1965 B. E. JOHNSON 3,204,707

SWIVEL AND FEED CONNECTION FOR A CORE DRILL Filed Aug. 15, 1962 F|G.I FIG. 250

so s4 30 INVENTOIR;

RT E. JO NSON ATT'Y United States Patent 3,204,707 SWIVEL AND FEED CONNECTION FOR A CORE DRILL Bert E. Johnson, 4423 N. Sheridan Road, Chicago 40, Ill. Filed Aug. 13, 1962, 'Ser. No. 216,431 6 Claims. (Cl. 173-57) The present invention relates to drilling equipment and has particular reference to a novel swivel and feed connection for a core drill, the connection from the standpoint of performance being of improved design and affording certain advantageous features that have hitherto been unattainable with conventional core drill mountings.

One of the principal features of the present invention, and one which contributes largely to such improved performance, resides in the consolidation of the water swivel unit and the feed mounting for the core drill so that the two are embodied in a single unit. By such an arrangement, considerable lost motion is eliminated and greater rigidity is made possible so that a smooth and steady pressure is applied to the work for fast penetration of the drill thereinto. A similar and related feature of the invention resides in the use of widely spaced bearing supports for the core drill supporting swivel drive shaft, the wide spacing of the bearing supports being made possible by reason of the consolidation of the swivel unit and the feed mounting. Incorporation of the water swivel in the feed mounting not only makes possible a Wider spacing of the shaft supporting bearings but also permits the use of larger and more substantial bearings without appreciably increasing the overall size of the drilling equipment or apparatus as a whole. This still further contributes toward rigidity, avoidance of chattering, ruggedness and durability. By utilizing a housing which incorporates both the water swivel and the feed mounting. Increased space is available within the housing and this space, according to the present invention, is utilized to accommodate the use of double seals at opposite ends of the drive shaft to insure against water leakage.

The invention also is concerned with a more effective distribution of the water or other liquid coolant in the vicinity of the working end of the core drill proper and, accordingly, it makes provision for the direction of jets of water forwardly and radially outwardly from the lower end of the drive shaft so that these jets will impinge against the inner cylindrical surface of the core drill proper and be carried to the abrasive annulus of the core drill in equal volume throughout the entire 360 extent thereof. By such an arrangement, spot cooling is avoided and dry friction is eliminated. This last-mentioned feature of the invention is particularly advantageous when a relatively long core drill extension is employed so that the abrasive annulus is widely separated from the point of water emergence from the drive shaft.

The provision of a drilling apparatus of the aforementioned character being among the principal objects of the invention, a further object is to provide an apparatus which is capable of being easily assembled and dismantled for purposes of inspection, replacement or repair of parts.

Another object of the invention is to provide a core drilling apparatus which embodies a combined water swivel and feed mounting and in which the driving motor for the apparatus is rigidly yet removably bolted to the housing with the motor shaft in alignment with and operatively connected to the water swivel drive shaft, thereby enabling an interchange of motors if desired. In connection with this last-mentioned object, it is contemplated that interchangeable pneumatic and electric motors be made available for driving purposes, the pneumatic motor being suitable for use generally where large size core drills are employed, and also in hazardous locations where electrical arcing must be avoided.

3,204,707 Patented depto 7, 1965 Numerous other objects and advantages of the invention, not at this time enumerated, will be apparent from a consideration of the following detailed description.

In the accompanying single heet of drawing forming a part of this specification, one illustrative embodiment of the invention has been shown.

In the drawing:

FIGURE 1 is a side elevational view of a core drill swivel and feed connection constructed according to the present invention, such connection being shown as operatively applied to a feed carriage;

FIGURE 2 is an enlarged fragmentary sectional view taken substantially centrally and vertically through the core drill and swivel connection of FIGURE 1 with certain parts broken away in the interest of clarity; and

FIGURE 3 is a bottom plan view of the structure of FIGURE 2 with the core drill proper removed.

Referring now to the drawing in detail, and in particular to FIG. 1, the combined water swivel and feed connection of the present invention has been designated in its entirety by the reference numeral 10. It involves in its general organization a generally cylindrical housing 12 from one end region of which there extends laterally a horizontal mounting leg 14 (see FIGS. 1 and 3). Although the core drill connection is designed for use at any selected angle, i.e., with its axis extending vertically, horizontally or at any in-between angle, for convenience of description and conformity with the disclosure of the drawing, the connection will be described herein as assuming the opposition wherein it is shown in FIGS. 1 and 2, that is, with the axis of the housing 12 extending vertically.

Rotatably disposed within the housing 12, in a manner that will be described in detail presently, is a vertical drive shaft 20, the lower end region of which projects endwise outwardly of the housing and carries a conventional core drill proper 22, hereinafter referred to simply as the core drill. A motor M is removably connected to the upper end of the housing 12 by bolts 24 and has its motor shaft 26 operatively connected to the drive shaft 20 in a manner that likewise will be made clear subsequently. Such motor may be either a conventional electric motor or a pneumatic motor. The mounting leg 14 is located at the upper end of the housing 12 and comprises a pair of oppositely directed mounting flanges, one of which is designated by the reference numeral 28 in FIG. 1. By means of the mounting flange 28 the leg together with the swivel and feed connection lit) may be secured to a vertically slidable feed carriage, a fragmentary portion of which is shown at 30 in FIG. 1. The feed carriage 30 forms no part of the present invention and may be of any suitable type. It is vertically slidable on guide posts and is caused to move vertically along the posts by either rack and pinion or by worm drive mechanism, as well understood in the art.

Referring now particularly to FIG. 2, the upper rim 32 of the cylindrical housing 12 is formed with an annular recess 34 and the motor M has a casing 36 which is flanged as at 38 so as to seat within the recess 34. The bolts 24 pass through the flange 33 with the result that the motor is securely fastened against lateral shifting.

The upper end 40 of the drive shaft 20 terminates substantially in the horizontal plane of the rim 32 and is provided with a relatively deep socket 42 into which the lower end of the motor shaft 26 projects. The socket 42 is provided with a vertical keyway 46 which slidably receives a key 48. The latter serves to connect together in driving relationship the motor shaft 26 and the drive shaft 20.

The motor casing 36 is formed with an internal annular recess 50 which receives therein upper ring bearings 52 for the motor shaft 26. The cylindrical housing 12 is provided with a central bore 54 therethrough. The lower end region of said bore is recessed internally as at 56 for reception therein of two superposed lower ring bearings 58 and 60 for the drive shaft 20. A retaining ring 62 is connected by'bolts 64 to the lower rim 66 of the housing 12 and serves to hold the two bearings 58 and 60 in position. It is to be noted that, although the upper bearing 52 is specifically associated with the motor shaft 26, it, in effect, constitutes a bearing for the upper end of the drive shaft 20 inasmuch as the shaft 26 is securely piloted in the socket 42 of the shaft 20. The portion of the shaft 20 that is Within the open-ended cylindrical housing 12 is thus given firm support against tilting movements and the shaft as a whole is accurately centered with respect to the housing, the wide spacing of the upper bearing 52 from the lower bearings 58 and 60 serving to inhibit wobbling of the shaft or chattering thereof under the influence of drilling operations.

The shaft 20 is held within the housing 12 against axial movement by means of a split ring 70 which seats within an annular groove 72 around the shaft and bears against a downwardly facing shoulder 74 on the shaft at the region Where the latter projects from the housing. The ring 70 is disposed within an annular recess 76 which is formed in the retaining ring 62.

Apart from the mounting arrangements thus far described, the housing 12 and the shaft 20 have associated therewith a water swivel connection and distribution system, the nature of which will be made clear after the core drill connection to the shaft 20 has been set forth. The lower projecting end of the shaft 20 is adapted selectively to receive thereon any one of a number of interchangeable core drills such as the core drill 30 (see FIGS. 1 and 2). This core drill is of conventional design and is in the form of an elongated open-ended seamless drill sleeve 82 to the lower open rim of which there is affixed at suitable matrix or crown 84, for example, a metallic matrix containing crushed or fragmented diamonds. Core drills of this character are commonly referred to as diamond core drills and are employed for drilling relatively hard substances, such as concrete or the like. Where softer substances are undergoing drilling, the drill sleeve may be provided with a crown which is devoid of diamond content.

The lower end of the drive shaft 20, i.e., the portion thereof which projects downwardly below the lower rim of the housing 12 is provided with a reduced portion 86 which is threaded as at 87 for reception thereover of conventional threaded shaft extensions or core drill size adapters (not shown), the extensions being employed where deep hole drilling is resorted to and the threaded adapters being employed where smaller diameter core drills are utilized. The upper end of the drill sleeve is adapted to be attached to the drive shaft 20 by means of a conventional expansion adapter including a nonthreaded frusto-conical adapter ring 88 and a threaded adapter ring 90. Between these two rings there is disposed the usual split expansion ring 92. The latter is provided with bevelled edges 93 which mate with cooperating bevelled edges 94 on the adapter rings 88 and 90. The shaft 20 is provided with a pair of diametrically disposed flats 95 in order to accommodate seizure of the shaft by a suitable tool, such as a wrench. Thus, as the threaded adapter ring 90 is threaded upwardly on the threaded portion 87 of the shaft 20, the non-threaded adapter ring 88 is forced against the shoulder 96 afforded by reason of the reduced portion 86 of the shaft, and the split expansion ring is forced radially outwardly to cause the upper end of the drill sleeve 82 to become affixed to the shaft 20 in concentric relationship thereto.

The water swivel connection for the core drill is afforded by means of a threaded water inlet opening 101) in the medial region of the housing 12, the opening being designed for connection to a flexible water supply line, such as the line 102, shown in FIG. 1. The water which is admitted to the interior of the housing 12 through the opening is confined within an annular water chamber 103 which is formed by two pairs of lip seals including an upper pair of seals 104 and a lower pair of seals 106. The four seals are identical and each is in the form of an elastomeric ring 1% of rubber, either natural or synthetic, or a rubber substitute. Each ring 1.08 is formed with an inwardly directed lip which has running contact with the surface of the shaft 2%) and is pressed thereagainst by means of a garter spring 112 or the like. A metal retainer 114 encompasses each ring 108 and is press-fitted within the bore of the housing 12. The seals of each pair are superposed upon each other and the lower pair of seals seats upon an internal shoulder 116 within the housing 20. The upper pair of seals seats upwardly against a spilt ring 118 which is carried in an internal groove 1211 in the housing wall.

The water or other coolant liquid which is admitted to the chamber 103 is adapted to flow through an internal passage 122 which is formed in the shaft 20 and includes an inclined lateral section 124 and an axial section 126. The lower end region of the axial section 126 is threaded as at 128 for reception therein of a dispersion plug 130, the function of which will be made clear presently. A pair of downwardly and outwardly inclined branch passages 132 establish communication between the passage 122 and the end face 134 of the shaft 20. The threaded portion 128 of the passage 122 is adapted selectively to receive therein an imperforate plug (not shown) and, when such a plug is so received in the threaded portion 128, the branch passages 132 establish a pair of outwardly and downwardly inclined diverging coolant jets at the lower end of the shaft 20.

The dispersion plug is generally of mushroom shape design and is provided with an enlarged head portion 136 and a threaded shank 138. A Y-passage 146 is formed in the plug 130 and creates a pair of relatively widely divergent coolant jets when the plug 130 is received within the passage 122.

The housing 12 is provided with an upper vent opening 142 above the level of the upper pair of seals 104 and embodies a similar lower vent opening 144 below the level of the lower pair of seals 1116 to allow any moisture which may find its way past the seals to escape from the housing, thus protecting the bearings 52, 58 and 61 from the adverse effect of moisture.

In the operation of the above-described swivel and feed connection, where relatively shallow holes are undergoing formation in the work and the core drill employed is of relatively short axial extent, neither the imperforate plug nor the perforate dispersion plug 130 will be employed and the coolant water flowing downwardly through the passage 122 will issue from the lower threaded end of the axial section 126 of the passage 122 and immediately flood the working area of the crown portion 84 of the core drill 80. Where the hole undergoing drilling is of moderate depth, an imperforate plug may be employed in the passage 122 so that all of the water will flow through the branch passages 132 and be directed toward the annulus undergoing drilling. Where relatively deep holes are involved, the dispersion plug 130 will be threadedly received within the passage 122 and the wide angle jets produced as a result thereof will cause the coolant water to be directed against the inner wall surface of any core drill extension which may be employed and also the inner surface of the drill sleeve 82 so that it will flow downwardly therealong and ultimately reach the annular drilling area. The dispersion plug 130 is useful where drilling on an incline is resorted to and its use precludes the possibility of draining away of the coolant water on one side of the annulus undergoing drilling and results in an even distribution of the water, thereby materially reducing friction and relieving the motor of undue strain.

The invention is not to be limited to the exact arrangemeat of parts shown in the accompanying drawing or described in this specification as various changes in the details of construction may be resorted to without departing from the spirit or scope of the invention. Therefore, only insofar as the invention has particularly been pointed out in the accompanying claims is the same to be limited.

Having thus described the invention, what I claim as new and desire to secure by Letters Patent is:

f. A water swivel and axial feed connection for an open-ended tubular core drill, said connection comprising a generally cylindrical open-ended tubular housing having a lateral mounting leg formed thereon adapted for connection to a reciprocable feed carriage, a motor having a casing fixedly secured to the upper rim of said housing, closing the same, and having a motor shaft projecting partially into the housing in concentric relation with respect thereto, a core drill drive shaft having its upper end region projecting into the housing in concentric relation with respect thereto and having its lower end region projecting downwardly through the lower rim of the housing, the upper end of said drive shaft terminating within the axial confines of the housing and adjacent to the upper end of the latter, the extreme lower end region of said drive shaft being adapted to have affixed thereto the upper end region of a core drill which the drill sleeve remaining spaced from the drive shaft and in concentric relation with respect thereto, the upper end of said drive shaft being provided with a relatively deep socket therein into which the lower end of the motor shaft projects and within which it is keyed, thereby establishing a driving connection between the motor shaft and the drive shaft, a thrust bearing surrounding said drive shaft and interposed between the drive shaft and the lower rim region of the housing for transmission of the downward thrust of the housing to the shaft while permitting rotation of the shaft within the housing, said housing being provided with a water inlet opening in the medial region thereof, and a pair of axially spaced lip seals surrounding the drive shaft and interposed between the drive shaft and housing above and below said water inlet opening, respectively, said lip seals, in combination with the drive shaft and housing, establishing an annular water chamber within the housing and in register with said water inlet opening, said drive shaft having a water passage therein including a lateral section in communication with said annular water chamber and an axial section opening through the lower end face of the drive shaft and adapted to conduct water from the chamber to the interior of the associated core drill.

2. A water swivel and feed connection as set forth in claim l and wherein said water passage in the drive shaft opens through the lower end face of the drive shaft centrally thereof and the axial section of the water passage is provided with a pair of branch passages which are inclined downwardly and outwardly in diverging relationship and open through said lower end face at diametrically disposed regions.

3. A water swivel and feed connection as set forth in claim it and wherein said water passage in the drive shaft opens through the lower end face of the drive shaft centrally thereof, the axial section of the water passage is provided with a pair of branch passages which are inclined downwardly and outwardly in diverging relationship and open through said lower end face at diametrically disposed regions, the lower end of said axial section of the water passage is threaded, and there is a removable plug threadedly received in the lower end of said axial section.

4-. A water swivel and feed connection as set forth in claim 3 and wherein said removable plug is formed with a Y-passage therein.

5. A water swivel and axial feed connection for an open-ended tubular core drill, said connection comprising a generally cylindrical open-ended tubular housing having a lateral mounting leg formed thereon adapted for connection to a reciprocable feed carriage, a motor having a casing fixedly secured to the upper rim of said housing, closing the same, and having a motor shaft projecting partially into the housing in concentric relation with respect thereto, a core drill drive shaft having its upper end regions projecting into the housing in concentric relation with respect thereto and having its lower end region projecting downwardly through the lower rim of the housing, the upper end of said drive shaft terminating within the axial confines of the housing and adjacent to the upper end of the latter, the extreme lower end region of said drive shaft being adapted to have affixed thereto the upper end region of a core drill with the drill sleeve remaining spaced from the drive shaft and in concentric relation with respect thereto, the upper end of said drive shaft being provided with a relatively deep socket therein into which the lower end of the motor shaft projects and within which it is keyed, thereby establishing a driving connection between the motor shaft and the drive shaft, a thrust bearing surrounding said drive shaft and interposed between the drive shaft and the lower rim region of the housing, said housing being provided with a water inlet opening in the medial region thereof, a pair of axially spaced lip seals surrounding the drive shaft and interposed between the drive shaft and housing above and below said water inlet opening, respectively, said lip seals, in combination with the drive shaft and housing, establishing an annular water chamber within the housing and in register with said water inlet opening, said drive shaft having a water passage therein including a lateral section in communication with said annular water chamber and an axial section opening through the lower end face of the drive shaft and adapted to conduct water from the chamber to the interior of the associated core drill, and a bearing surrounding said motor shaft and interposed between the motor shaft and the motor casing immediately above the level of the upper rim of the housing.

6. A water swivel and feed connection as set forth in claim 5 and wherein the upper rim of said housing is formed with an annular recess, and there is a seating flange on the motor casing seating within and filling said annular recess.

References (lifted by the Examiner UNITED STATES PATENTS 2,870,994 1/59 Klapka 173--57 2,996,061 8/61 Miller -20 3,003,493 10/61 Miller 125-20 BROUGHTON G. DURHAM, Primary Examier. 

1. A WATER SWIVEL AND AXIAL FEED CONNECTION FOR AN OPEN-ENDED TUBULAR CORE DRILL, SAID CONNECTION COMPRISING A GENRALLY CYLINDRICAL OPEN-ENDED TUBULAR HOUSING HAVING A LATERAL MOUNTING LEG FORMED THEREON ADAPTED FOR CONNECTION TO A RECIPROCABLE FEED CARRIAGE, A MOTOR HAVING A CASING FIXEDLY SECURED TO THE UPPER RIM OF SAID HOUSING, CLOSING THE SAME AND HAVING A MOTOR SHAFT PROJECTING PARTIALLY INTO HE HOUSING IN CONCENTRIC RELATION WITH RESPECT THERETO, A CORE DRILL DRIVE SHAFT HAVING ITS UPPER END REGION PROJECTING INTO THE HOUSING IN CONCENTRIC RELATION WITH RESPECT THERETO AND HAVING ITS LOWER END REGION PROJECTING DOWNWARDLY THROUGH THE LOWER RIM OF THE HOUSING, THE UPPER END OF SAID DRIVE SHAFT TERMINATING WITHIN THE AXIAL CONFINES OF THE HOUSING AND ADJACENT TO THE UPPER END OF THE LATTER, THE EXTREME LOWSER END REGION OF SAID DRIVE SHAFT BEING ADAPTED TO HAVE AFFIXED THERETO THE UPPEREND REGION OF A CORE DRILL WHICH THE DRILL SLEEVE REMAINING SPACED FROM THE DRIVE SHAFT AND IN CONCENTRIC RELATION WITH RESPECT THERETO, THE UPPER END OF SAID DRIVE SHAFT BEING PROVIDD WITH A RELATIVE DEEP SOCKET THEREIN INTO WHICH THE LOWER END OF THE MOTOR SHAFT PROJECTS AND WITHIN WHICH IT IS KEYED, THEREBY ESTABLISHING A DRIVING CONNECTION BETWEEN THE MOTOR SHAFT AND THE DRIVE SHAFT, A THRUST BEARING SURROUNDING SAID DRIVE SHAFT AND INTERPOSED BETWEEN THE DRIVE SHAFT AND THE LOWER RIM REGION OF THE HOUSING FOR TRANSMISSION OF THE DOWNWARD THRUST OF THE HOUSING TO THE SHAFT WHILE PERMITTING ROTATION OF THE SHAFT WITHIN THE HOUSING, SAID HOUSING BEING PROVIDED WITH A WATER INLET OPENING IN THE MEDIAL REGION THEREOF, AND A PAIR OF AXIALLY SPACED LIP SEALS SURROUNDING THE DRIVE SHAFT AND INTERPOSED BETWEEN THE DRIVE SHAFT AND HOUSING ABOVE AND BELOW SAID WATER INLET OPENING, RESPECTIVELY, SAID LIP SEALS, IN COMBINATION WITH THE DRIVE SHAFT AND HOUSING, ESTABLISHING AN ANNULAR WATERCVHAMBER WITHIN THE HOUSING AND IN REGISTER WITH WATER CHAMBER WITHIN THE HOUSING AND IN REGISTER WITH PASSAGE THEREIN INCLUDING A LATERAL SECTION IN COMMUNICATION WITH SAID ANNULAR WATER CHAMBER AND AN AXIAL SECTION OPENING THROUGH THE LOWER END FACE OF THE DRIVE SHAFT AND ADAPTED TO CONDUCT WATER FROM THE CHAMBER TO THE INTERIOR OF THE ASSOCIATED CORE DRILL. 